Field of the Invention
The present invention is directed to a pre-filled syringe assembly adapted for the dispensing and delivery of a fluid. More particularly, the present invention is directed to a pre-filled syringe assembly having a telescopic plunger rod having a pull-out safety arrangement wherein the plunger rod arrangement results in a smaller packaging footprint allowing for reduced storage space. The present invention is also directed to a packaging system for a pre-filled syringe assembly that prevents unintended actuation of the plunger rod and reduces the likelihood of tampering of the syringe contents.
Description of Related Art
Conventional syringes are well known to be used in connection with a vial of a medication, wherein the user draws the fluid into the syringe immediately prior to injection and delivery of the fluid to the patient. A conventional syringe typically includes a syringe barrel with an opening at one end and a plunger mechanism disposed through the other end. The plunger mechanism typically includes a plunger rod extending through the barrel, with a plunger head or stopper at the end of the plunger rod within the barrel and with a finger flange at the other end of the plunger rod extending out of the barrel. In use, the plunger rod is retracted through the syringe barrel to fill the syringe barrel with a fluid, such as a medication, with the plunger rod extending out from the rear end of the syringe barrel. For delivery of the medication to a patient, the opening of the syringe barrel is adapted for fluid communication with a patient, such as through a hypodermic needle fitted at the front end of the syringe barrel or through a luer-type fitting extending from the front end of the syringe barrel for attachment with a fluid line of a patient. Upon depression of the plunger rod, the plunger rod and stopper travel through the syringe barrel, thereby forcing the contents of the syringe out through the opening at the front end for delivery to the patient. Such an operation is well known in the medical field, and medical practitioners have become well accustomed to the use of such common fluid delivery procedures through standard syringes.
Oftentimes, hypodermic syringes may be packaged as “pre-filled” devices, wherein the syringe is pre-filled with medication prior to being packaged and delivered to the end user. In this manner, there is no need for the user to fill the device prior to injection, thereby saving time for the end user and maintaining consistent volumes for delivery. Pre-filled syringes and pre-filled metered dose syringes are often filled with narcotics or other drugs at a production facility, packaged, and then shipped to a medical facility. Once at the facility, these syringes are often placed in controlled storage and/or locked cabinets to reduce theft of the syringes themselves and/or theft of the contents of these syringes. The space within these controlled storage locations is often limited, thus there is a need for a syringe assembly that has a smaller packaging footprint, to reduce the storage space required for containing this syringe. It is also desirable to produce syringes that are uniform in terms of an outer surface shape to allow for stacking of the syringes within the storage cabinet.
Even though measures, such as controlled storage, are taken to ensure the contents of these syringes remain intact, the risk still remains that the syringe contents can be tampered with and/or stolen and replaced with a saline solution. One technique for preventing tampering is the use of a snap cap for the tip cap that makes a snapping noise when removed from the syringe assembly. Conventional tamper-proof caps for pre-filled syringes may include a top member concentrically disposed in a generally cylindrical sleeve member and connected by frangible elements to the sleeve member. Conventional outer caps for pre-filled syringes cover a cylindrical cover cap which connects with the top wall of a holding member through a frangible portion. The cylindrical cover cap may be broken from the top wall of the holding member for tampering prevention/tamper-proof evidence.